List of papers, book chapters, conference presentations, and other publication materials from Thermal Sciences and Materials Branch, Materials and Manufacturing Directorate, AFRL List of papers, book chapters, conference presentations, and other publication materials from Thermal Sciences and Materials Branch, Materials and Manufacturing Directorate, AFRL

This set of lecture notes explains electro-thermal and thermo-electric effects as they occur in semiconductor materials and devices. This set of lecture notes explains electro-thermal and thermo-electric effects as they occur in semiconductor materials and devices.

THREE-DIMENSIONAL CODES FOR EXACT TRANSIENT HEAT CONDUCTION SOLUTIONS IN PARALLELEPIPEDSPrepared for Sandia National Laboratories Albuquerque, NM Purchase Order No. 30629 James V. Beck Beck Engineering Consultants Company 1935 Danbury W. Okemos, MI 48864-1873 Tel. Number: 517-349-6688 E-mail: jvb@BeckEng.com June 15, 2002PERSONNELSeveral engineers and mathematicians participated in the development of V2000A and subroutine COND3D by Beck Engineering Consultants Co. Most of the coding for this program was done under the 1999-2000 contract from Sandia National Laboratories that was administered by Dr. Kevin Dowding of Sandia. The personnel are listed in alphabetical order with a partial description of the individual contributions.Donald Amos, (Retired applied mathematician, Sandia Nat. Labs.) Numerical and analytical integration. Theoretical support. James V. Beck, (Prof. Emeritus Mech. Eng., MSU; President, Beck Engineering Consultants Co.) Overall direction and coordination of the…

This tool is an eigenvalue solution for phonon dispersion in a 1D chain of atoms, bases and layers with a constant harmonic potential. You can design a 1D system of arbitrary masses with multiple bases. No attempt has been made to separate the branches. 1-D Chain of atoms, bases and layers to produce phonon dispersion

hotSPICE is a linear thermal circuit simulation tool. Resistors, capacitors, temperature sources and heat sources can be used in any combination to model thermal problems. Both steady-state and transient analyses can be performed. Plots can be generated for temperature at any node in the circuit, as well for heat transfer across any temperature source. hotSPICE is intended for undergraduate heat transfer students. Linear thermal circuit simulation tool for both steady-state and transient problems

Metal hydrides can be used to store hydrogen on-board fuel cell vehicles, but the process of fracture that the material undergoes when exposed to hydrogen makes metal hydrides poor conductors of heat due to the particulate nature of fractured metal hydride. The fracture process by which particles are generated results in irregular faceted morphology that are difficult to describe quantitatively from experimental data. The isotropic random fracture model, rndmfrc, generates convex polyhedra by the sequential fracture of isotropic, randomly oriented planes, and can be used to model particles composing metal hydride powder. The isotropic random fracture model assumes (1) planar surfaces are formed from instances of fracture, (2) planes of fracture have isotropic statistical orientation and position throughout the material, and (3) fracture of any individual particle can terminate during the sequential fracture process according to a criterion. This tool enables modeling of discrete metal…

2D Ideal Gas Molecular DynamicsBy specifying a temperature difference between the left and right boundaries the following parameters of a ideal gas system will be calculated:Average Ensemble PositionAverage Ensemble VelocityMean VelocityAverage Ensemble TemperatureAverage Particle SpeedInterface PressureThermal Conductance Simulation of a 2d molecular gas with specified temperature boundary conditions

Metal hydrides can be used to store hydrogen on-board fuel cell vehicles, but the process of fracture which such materials undergo when exposed to hydrogen makes them poor conductors of the heat generated during hydriding. This fracture process creates particles having irregular faceted shapes that are difficult to quantitatively generalize directly from experimental microscopy data. This tool enables modeling of discrete metal hydride particles under the approximation of planar fracture with isotropic orientation and position. Go to this thermalHUB topics page for more details about the tool. Metal hydrides can be used to store hydrogen on-board fuel cell vehicles, but the process of fracture which such materials undergo when exposed to hydrogen makes them poor conductors of the heat generated during hydriding. This fracture process creates particles having irregular faceted shapes that are difficult to quantitatively generalize directly from experimental microscopy data. This tool…

This paper considers a classical linear, transient heat conduction problem set in Regions 1 and 2 defined by the half planes x>0 and x0 and x

Abstract Two linear, transient heat conduction problems set in quadrants 1 and 2 of the (x,y) plane are solved. In each problem, the quadrants have distinct, constant physical properties and are separated by an infinitely thin thermal resistance along the y-axis. Each region is initially at zero temperature. In Problem I, constant fluxes are specified along the x-axis boundaries to complete the problem definition; while in Problem II, constant temperatures are specified.An attempt at a solution to Problem I by classical application of the Laplace transform results in an integral representation for the temperature in each quadrant. Unfortunately the integrals only converge in 45 degree wedges which are close to the x-axis. However, a modification in the path of integration into the complex plane leads to a complete solution in terms of integrals of co-error functions of a complex variable. Details on high accuracy numerical evaluation of error functions and quadratures are provided.…

A matlab script that is useful for calculating eigenvalues of cartesian geometries for boundary conditions of the first second and third kinds (XIJ) is provided. A matlab script that is useful for calculating eigenvalues of cartesian geometries for boundary conditions of the first second and third kinds (XIJ) is provided.J. V. Beck and A. Haji-Sheik

The analytical solutions of Carslaw and Jaeger arecataloged using the Beck and Litkouhi heat conduction notation. The analytical solutions of Carslaw and Jaeger arecataloged using the Beck and Litkouhi heat conduction notation.This document was contributed by James V. Beck and Elaine P. Scott.Heat Conduction Using Green\'s Functions, J. Beck, K. Cole, A. Haji-Sheikh, and B. Litkouhi, Hemisphere, 1992

This simulation tool solves simple 1D phonon transport problems by the atomistic Green's function (AGF) method. A phonon transmission function is derived from Green's functions and, using the transmission function, the thermal conductance integral in Landauer form is computed. Within the theoretical framework of the AGF, the required inputs to calculate conductance are the masses of atoms and an appropriate interatomic potential. Homogeneous and heterogeneous atomic chains can be simulated. Calculation of Thermal Conductance of an Atomic Chain

This software computes thermal conductivities of single-wall carbon nano-tubes (SW-CNT) via NEMD (non-equilibrium molecular dynamics) method. Two versions of the same program are available: a tool version for fast set-up and simulations and a step-by-step tutorial for students. The procedure used to compute the conductivity is outlined in the tutorial version of the program; more details can be found in E. Chiavazzo, P. Asinari, "Enhancing surface heat transfer by carbon nanofins: towards an alternative to nanofluids?" Nanoscale Research Letters 6 (2011) 249. The numerical solution is obtained using the GROningen MAchine for Chemical Simulations (GROMACS). In this program, we use harmonic potential for the phononic thermal transfer (OPLS-AA force field).  Compute thermal conductivity of single-walled carbon nano-tubes via NEMD method